Magneto mechanism



R. E. PHELON MAGNETO MECHANISM Filed March 2, 1955 TOR RUSSELL PHELON BY TTORNEYS United States PatentOfiice 2,847,492 Patented Aug. 12, 1958 .The' invention relatesgenerally to .a magneto of .the flywheel-typeand it relates more :particularlytto a magneto I and engine assembly which includes an improved mounting means for the stator :of the magneto. A mechanism embodying thepresent invention is in some respects similar :to' that set. forth' inthe copending application of Russell E. Phelon, Serial No. 492,158, filed March 4, 1955, and entitled Magneto Mechanism.

The general object of the present invention is to provide a magneto .and engine assembly having the simplicity and low cost of that set forth invthe said application so far as concerns the mounting of the core of the stator and also so constructed that at least a portion of the breaker mechanism for the magneto is in-a space directly below the core with a resultant substantial reduction in longitudinal dimensions.

Inithe 'drawingI have shown in detail apreferred embodiment of the invention, but it will be understood that various changes may be made from the construction shown, and'that the drawing is not to be construed as defining or limiting the scope of theinvention, the claims forming a part of this specification'being relied upon for that purpose.

Of the drawing:

Fig. 1 is a-transverse sectional view of amagneto embodying the invention, the viewbeing taken along the line '11 of Fig. 2 and the breaker mechanism cover being omitted.

Fig. 2 is a longitudinal sectional view taken along the line 2--2 of Fig. -1.

Fig. 3 .is' a transverse sectional view taken along the line 3---3 of Fig. 2.

Fig. 4 is a fragmentary sectionalview taken along the line 44 of Fig. '1.

Referring to the drawing, it will be apparent that the magneto shown is of the typewherein the rotoris carried by or is formed as a part of the flywheel and wherein the rotor surrounds, or at least partly surrounds, the stator. Within the scope of the present invention the rotor and the stator may be widely'varied not only as to mechanical details but also as to magnetic circuits. Except as to the hereinafter described features of novelty, the-rotor and stator'structures as shown and described are intended to 'be merely exemplary.

The stator of'the magneto 'and the breaker mechanism to which'the invention more particularly relates are carried or adapted to be carried "by an engine frame or plate 10 preferably :having a .hub 12 which provides a bearing for a rotatable shaft 14, the shaft extending through and projecting lbeyond the'hub. The shaft 1 4 may .be an-extension of the crankshaft of the'engine with whichxthe magnetoist'o be used, and inanyeventit is rotated in timed relationship with .the'engine. .The stator comprises amagnetic core 16 which has parallel front and rear faces-.and .ispreferably laminated. .Said core 16 .is constructed and arranged to provide a plurality of circularlyspacedpoles having arcuate faces-concentric with the-axis of the .shaft 14..and equidistant therefrom.

As shown, the core 16 has three poles 18, 20 and'22, and primary and secondary coils 24 'and 26 surround the intermediate pole 20. The primary coil has a relatively small number of turns, as for instance 175, and the secondary coil has a relatively large number of turns, as for instance 10,000.

The primary coil 24 is suitably grounded at one end by means not shown, and the ungrounded end of said coil isconnected by means of an insulated conductor 28 with a suitable circuit making and breaking mechanism 30. The circuit making and breaking mechanism 30 may be mounted directly upon the core 16 and it is so shown. When said mechanism is mounted upon the core, it is preferably enclosed within and supported by a box 32 connected with said core by rivets 34, 34. Said'mechanism 30 and said box 32 are hereinafter more fully described. The secondary coil 26 is also suitably grounded by means not shown, and it is provided at its ungrounded end with an insulated conductor 36 by means of which it is connectible with the spark plug of the engine.

The rotor of the magneto includes a flywheel 38 which is connected with the shaft 14 so as to be rotatable therewith. The flywheel is preferably formed of nonmagnetic material and it is shown as having a disc-like outer wall carrying an annular flange 40 which surrounds the beforedescri'bed-stator. The inner or internal face of the annular flange 40 is preferably cylindrical at least in part.

Located within a recess in the flange 40 of the flywheel is a permanent magnet 42 and two similar pole pieces 44, '44 which are formed of magnetic metal and which engage the magnet at opposite ends thereof. The inner faces of the pole pieces are arcuate and are located to move in close proximity to the outer faces of the stator poles 1'8, 2'0 and 22.. The flywheel flange is provided with a counterweight 46 opposite the magnet and the pole pieces. As shown, the magnet and the pole pieces and the counterweight are held in place by the metal of the flange which is cast around them.

During each rotation, the magnet and the pole pieces therefor cooperate with thepoles of the stator to establish a magnetic circuit in one'direction through the center pole 20 and through the coils thereon and then to establish a similar circuit in the opposite direction. Thus the direction of .the magnetic circuit is suddenly reversed and a maximum value of voltage is established in the primary coil 24. break the circuit in the primary coil at approximatelythe instant of maximum voltage there, thus generating a high voltage in the secondary coil 26 which is connected with the spark plug, not shown.

The laminated core 16 has a relatively large opening 48 therein as best shown in Fig. 3, the opening receiving and engaging a portion of the hub 12 on the engine frame or plate 10. Said hub 12 is integral with the plate 10 and it has an outer or front face and it has a central axis coinciding with the shaft axis, and said hub is provided with a cylindrical periphery which is concentric with said axis and which is unobstructed at its front end. At'least a portion of the interior surface of the core opening 48 directly engages said cylindrical periphery of said 'hub 12 so as to prevent any relative movement of said plate perpendicularly to the hub axis. Said hub 12 and core 16 are so related to each other that said core is longitudinally movable intoits fully engaged position on said hub. As shown, the hub 12 has a portion 50 of reduced diameter and the core engages andfits the said portion. As illustrated in Fig. 2, a shoulder 52 is provided by the reduced hub portion 50 and this shoulder engages 'the core and locates it longitudinally. With the construction shown, the hub-12 serves to at least partly locate and to at least partly support the core 16.

The breaker mechanism is timed to Means are provided for preventing rotative movement of the core 16 on the hub 12. The portion 50 of the hub partly locates the core 16, but it does not prevent rotative movement of the core and the entire stator around said hub. Such rotative movement is prevented by at least one screw 54 extending through a suitable hole in the core, and preferably there are two such screws. Bosses 56 are provided on the engine plate which have their front faces in engagement with the rear face of the core. Said bosses have threaded holes for receiving said screws 54, 54. One screw and boss are shown in Fig. 4.

As thus far described, the connection of the core with the engine plate and more particularly with the hub of said engine plate is in accordance with the invention set forth in said application Serial No. 492,158. The improvement constituting the present invention will now be more specifically described.

As best shown in Fig. 3, said opening 48 in the core 16 is so related to one edge of said core, preferably the bottom edge, that said hole intersects said edge. The relationship is such that at least one zone of the interior surface of the hole extends around the hub periphery through substantially less than 360 but nevertheless through more than 180, and as shown said surface at said zone so extends through about 270. The core 16 therefore has a gap of substantially less than 180 wherein a portion of the periphery of the hub is exposed adjacent the lower edge of the core. The shoulder 52 is so located that only a small rear portion of the core 16 engages the cylindrical portion 50 of the hub, a major portion of the core 16 being at the front of the plane of the front face of the hub. Thus the engagement of the core with the hub not only prevents any movement of said core perpendicularly to the hub axis as before stated and as set forth in said application, but it also provides a space directly below the core and closely adjacent the shaft for receiving the breaker mechanism or at least a portion thereof.

In accordance with the invention, the breaker mechanism 30 is so located that at least a portion thereof is in the said space or gap directly below and closely adjacent the core and is behind th plane of the front face of said core. As shown and as preferred, the breaker mechanism is directly supported on the core and the box 32 when provided is connected with said core by said rivets 34, 34. The upper rear portion of the box 32 is cut away or notched to receive the lower portion of the core, but below said core and below said hub 12 the box 32 has a rear wall 58 spaced substantially rearwardly from the plane of the front face of the core. Said rear wall has an arcuate upper edge 60 which conforms to the curvature of the hub portion 50 but said edge is nevertheless slightly spaced radially from said hub portion. Preferably and as shown, a clearance is provided between said rear wall 58 of the box and said hub shoulder 52.

The presently preferred breaker mechanism is shown in detail in Figs. 1 and 2. The said mechanism includes a stationary breaker point 62 carried by a bracket 64 secured by a screw 66 to the rear wall 58 of the box and thus grounded. The mechanism includes a movable breaker point 68 carried by a rocker arm 70 mounted on a longitudinal pivot pin 72. The pin 72 has a portion 74 which has a reduced diameter and is entered in a hole in the rear box wall 58. The rocker arm 70 has an extension 76 which is engaged by a cam 78 on the shaft 14, said cam being so located that a substantial portion thereof is behind the plane of the front face of the core 16. This position of the cam 78 is made possible by the location of the core with only the rear portion thereof in engagement with the hub. Said rocker arm 70 is shown as being so located that the extension 76 thereof engages the cam 78 about midway of its length, at least a portion of said arm also being behind said plane through the front face of the core. A spring 80 serves to bias the rocker arm to move the point 68 into engagement with the point 62 and the spring, or an auxiliary conductor as,

sociated therewith, serves to provide an electrical connection between the conductor 28 and the breaker point 68. The conductor 28 and the spring 80 are electrically connected with each other by a screw 82 extending through the wall of the box 32 and insulated from said wall. The details of the connection between the conductor and the spring may be as fully shown inthe application of Russell E. Phelon and John F. Martin, Serial No. 540,178, filed October 13, 1955.

The walls of the box 32 are provided at the front thereof with a rab'bet for receiving a front cover 84 suitably held in place by means not shown. The cover has a hole through which the shaft 14 extends.

During each rotation, the magnet and the pole pieces therefor cooperate with the poles of the stator to establish a magnetic circuit in one direction through the center pole and through the coils thereon and then to establish a similar circuit in the opposite direction. Thus the direction of the magnetic circuit is suddenly reversed and a maximum value of voltage is established in the primary coil 24. The breaker mechanism is timed to break the circuit in the primary coil at approximately the instant of maximum voltage there, thus generating a high voltage in the secondary coil 26 which is connected with the spark plug, not shown.

By means of a conductor 86, shown in Figs. 1 and 3, a condenser 88 is connected in parallel with the breaker mechanism in accordance with customary practice. As shown, the condenser is attached to the box 32 by means of a clip 90 held by a screw 92. The side wall of the box is notched to admit a portion of the clip 90, said clip being behind the box cover 84 when said cover is in place.

From the drawing and from the foregoing description it will be evident that a substantial portion of the breaker mechanism is behind the plane of the front face of the core and directly below and closely adjacent said core and said shaft 14. This enables the flywheel to be located nearer the engine plate 10 than would otherwise be possible and reduces the overall longitudinal dimension of the magneto.

The invention claimed is:

1. A magneto and engine assembly comprising in combination, a stationary engine plate including an outwardly projecting integral hub having a front face and having a central axis, said hub being provided with a cylindrical periphery concentric with said axis and unobstructed at its outer end, a rotatable shaft concentric with said hub axis and having a portion extending through and projecting beyond said front face of the hub, a magnetic core formed of laminated metal and shaped to provide a plurality of poles having faces equally spaced from the axis of the shaft, said core having a relatively large partly cylindrical opening therein adjacent one edge thereof which opening is so located that it receives and fits the cylindrical periphery of said hub through substantially more than but substantially less than 360 so as to provide a gap in said core adjacent said hub, means for holding said core in a fixed position on said engine plate, primary and secondary coils surrounding one of said poles of the core and cooperating With said core to constitute a stator, a breaker cam on said shaft located with a major portion thereof behind the plane of the front face of the core, a breaker mechanism electrically connected with said primary coil and operable by said cam which breaker mechanism is located with at least a portion of the cam engaging element thereof in said gap in the core and between the front and back planes of said core, and a rotor carried by the projecting portion of said rotatable shaft and including a magnet and pole pieces movable in close proximity to said pole faces of the stator.

2. A magneto and engine assembly comprising in combination, a stationary engine plate including an outward ly projecting integral hub having a front face and having a central axis, said hub being provided with a cylindrical periphery concentric with said axis and unobstructed at its outer end, a rotatable shaft concentric with said hub axis and having a portion extending through and projecting beyond said front face of the hub, a magnetic core formed of laminated metal and shaped to provide a plurality of poles having faces equally spaced from the axis of the shaft, said core having a relatively large partly cylindrical opening therein adjacent one edge thereof which opening is so located thatit receives and fits the cylindrical periphery of said hub through more than 180 but substantially less than 360 so as to provide a gap in said core adjacent said hub, means for holding said core in a position with the major portion thereof at the front of the plane of the front face of the hub, primary and secondary coils surrounding one of said poles of the core and cooperating with said core to constitute a stator, a breaker cam on said shaft located with a major portion thereof behind the plane of the front face of the core, a breaker mechanism electrically connected with said primary coil and operable by said cam which breaker mechanism is adjacent said edge of the core and is supported on said core and which breaker mechanism is located with a major portion thereof in said gap in the core and behind said plane of the front face of said core, and a rotor carried by the projecting portion of said rotatable shaft and including a magnet and pole pieces movable in close proximity to said pole faces of the stator.

3. A magneto and engine assembly comprising in combination, a stationary engine plate including an outwardly projecting integral hub having a front face and having a central axis, said hub being provided with a cylindrical periphery concentric with said axis and unobstructed at its outer end, a rotatable shaft concentric with said hub axis and having a portion extending through and projecting beyond said front face of the hub, a magnetic core formed of laminated metal and shaped to provide a plurality of poles having faces equally spaced from the axis of the shaft, said core having a relatively large partly cylindrical opening therein adjacent one edge thereof which opening is so located that it receives and fits the cylindrical periphery of said hub through more than 180 but substantially less than 360 so as to provide a substantial gap in said core so that the remainder of the periphery of the hub is exposed adjacent said edge of the core, means for holding said core in a position with a major portion thereof at the front of the plane of the front face of the hub, primary and secondary coils surrounding one of said poles of the core and cooperating with said core to constitute a stator, a breaker cam on said shaft located with a major portion thereof behind the plane of the front face of the core, a breaker mechanism supported on said core and electrically connected with said primary coil and operable by said cam which breaker mechanism is adjacent said edge of the core and is adjacent said exposed portion of the periphery of the hub, said breaker mechanism being at least partially in said gap in the core and being located with a major portion thereof behind said plane of the front face of said core, and a rotor carried by the projecting portion of said rotatable shaft and including a magnet and pole pieces-movable in close proximity to said pole faces of the stator.

4. A magneto and engine assembly comprising in combination, a stationary engine plate including an outwardly projecting integral hub having a front face and having a central axis, said hub being provided with a cylindrical periphery concentric with said axis and unobstructed at its outer end, a rotatable shaft concentric with said hub axis and having a portion extending through and projecting beyond said front face of the hub, a

magnetic core formed of laminated metal and shaped to provide a plurality of poles having faces equally spaced from the axis of the shaft, said core having a relatively large partly cylindrical opening therein adjacent one edge thereof which opening is so located that it receives and fits the cylindrical periphery of said hub through more than but substantially less than 360 so as to provide a gap in said core adjacent said hub, means for holding said core in a position with a major portion thereof at the front of the plane of the front face of the hub, primary and secondary coils surrounding one of said poles of the core and cooperating with said core to constitute a stator, a breaker cam on said shaft located with a major portion thereof behind the plane of the front face of the core, a box supported entirely on said core adjacent said edge thereof which box is located with a major portion thereof behind said plane of the front face of said core and is located at least partially in said gap in the core, a breaker mechanism electrically connected with said primary coil and operable by said cam which breaker mechanism is within and supported by said box and is located with a major portion thereof behind said plane of the front face of said core, and a rotor carried by the projecting portion of said rotatable shaft and including a magnet and pole pieces movable in close proximity to said pole faces of the stator.

5. A magneto and engine assembly comprising in combination, a stationary engine plate including an outwardly projecting integral hub having a front face and having a central axis, said hub being provided with a cylindrical periphery concentric with said axis and unobstructed at its outer end, a rotatable shaft concentric with said hub axis and having a portion extending through and projecting beyond said front face of the hub, a magnetic core formed of laminated metal and shaped to provide a plurality of poles having faces equally spaced from the axis of the shaft, said core having a relatively large partly cylindrical opening therein adjacent one edge thereof which opening is so located that it receives and fits the cylindrical periphery of said hub through more than 180 but substantially less than 360 so as to provide a gap in said core adjacent said hub, means for holding said core in a position with the major portion thereof at the front of the plane of the front face of the hub, primary and secondary coils surrounding one of said poles of the core and cooperating with said core to constitute a stator, a breaker cam on said shaft located with a major portion thereof behind the plane of the front face of the core, a box supported entirely on said core adjacent said edge thereof which box has an upper portion in direct engagement with the front face of the core and has a lower portion at least partially within said gap in the core, said lower portion of said References Cited in the file of this patent UNITED STATES PATENTS Alstrom Jan. 6, 1948 Brownlee Jan. 22, 1952 

